The present invention is concerned with the automatic changing of cutting inserts on toolholders when they become damaged or worn during a machining cycle.
In the machining of materials utilizing toolholders with replaceable cutting inserts, a great deal of work has been done in trying to make the machining process a very efficient one. One of the inefficiencies of the machining system concerned the changing of the cutting insert when it became dull or worn, and even more importantly, the changing of the cutting insert when it fractured during the machining cycle.
When the insert can no longer be used in the cut, it is necessary to back the toolholder out from the workpiece and either index the cutting insert to another cutting edge or replace it in its entirety. This is usually done by the operator coming in and unclamping the insert with regular or special tooling, picking up the hot insert, utilizing gloves or other special equipment, and indexing or replacing the insert without introducing too much contamination, dirt or debris to the insert seat.
The insert can then be clamped by the operator and the toolholder returned to the workpiece for a test cut to determine if the new cutting edge has the same dimensional cutting ability as the previous cutting edge. If not, the machine tool must be readjusted so as to make up for any tolerancing differences.
In addition to the insert becoming dull and worn, the more catastrophic situation, and the most inefficient, from the standpoint of machining systems, occurs when the end of the life of the insert happens through breakage while the insert is still involved in the cutting of the workpiece. This situation can lead to severe damage, which may cause the scrapping of the workpiece, in addition to the lost time and other things associated with the changing of the insert.
More recently, studies have indicated that there are systems which may measure when a cutting insert is reaching the end of its useful life. When this occurs, a signal may be generated, indicating that the insert should be changed rather than risk any further machining operations.
It is an object of the present invention to provide an automatic insert changer whenever a signal has been generated indicating that the cutting insert has completed its useful life.
It is a further object of the present invention to more efficiently replace the cutting insert than when completed by a machine operator
It is a further object of the present invention to provide a toolholder and insert cartridge to provide for long periods of unattended machining operations.